CN104557999B - A kind of novel thin film deposition of aluminum presoma and preparation method thereof - Google Patents

Abstract

A kind of novel thin film deposition of aluminum presoma, which is characterized in that there is the molecular structure of (I) following structural formula, wherein R₁、R₂、R₃、R₄、R₅Indicate hydrogen atom, C₁~C₆Alkyl, C₂~C₅Alkenyl, C₃~C₁₀Naphthenic base, C₆~C₁₀Aryl or-Si (R₀)₃And the halogenic substituent group of above-mentioned group, wherein R₀For C₁~C₆Alkyl or its halogenic substituent group, R₁、R₂、R₃、R₄、R₅It is identical or different.According to the present invention, have developed the film deposition precursor body that thermostabilization is good, is not easily decomposed, convenient for storing and transporting, high-temperature volatile is good, can by CVD/ALD technique prepare aluminum containing film for example aluminum metal film, the sull containing aluminium, the nitride film containing aluminium, containing the alloy firm of aluminium, filming performance is excellent.

Description

A kind of new thin film deposition aluminum precursor and preparation method thereof

technical field

The invention relates to a novel thin-film deposition aluminum precursor, a preparation method and application thereof, and is especially suitable for atomic layer deposition technology, and relates to the field of semiconductor and nanotechnology. Specifically, it relates to a thin-film deposition aluminum precursor material that is stable in properties, not easily decomposed, has excellent high-temperature volatility, and is easy to store and transport.

Background technique

With the rapid development of semiconductor technology, the manufacturing process and technology of devices have also changed, thin films are more and more used, and the corresponding thin film manufacturing technology has also been continuously improved. Compared with traditional technology, chemical vapor deposition (CVD) There are many advantages, and atomic layer deposition (ALD) technology has more advantages in some areas.

In CVD/ALD process technology, the properties of the precursors are critical. At normal temperature, the precursor should have high stability to facilitate production, transportation and storage; at the same time, it should have high volatility so that the precursor can enter the deposition chamber with the carrier gas. In addition, for CVD precursors, there should be better thermal decomposition properties at higher temperatures (deposition temperatures) in order to deposit suitable films; for ALD precursors, at higher temperatures It should still have high thermal stability (deposition temperature) to avoid thermal decomposition by itself, while having good reactivity with another source for deposition into a film. Due to the strict requirements on the stability and volatility of precursors, there are not many precursors that can really be used for film formation. The invention of suitable precursors has become one of the key technologies of CVD/ALD.

As far as the deposition technology of aluminum and aluminum-containing films is concerned, the stability of aluminum precursors has always been a technical problem in the art. Abroad, the 2003 US patent US20030224152A1 discloses a series of CVD precursors such as alkyl aluminum, alane and amine complexes; 2007 patent WO2007/136184A1 discloses aminoboryl alane complexes as CVD precursors. In the ALD technology, the precursors used are also the aforementioned limited precursors that can be used in CVD. In China, Patent Application No. 201310450417.3 discloses a method for depositing an aluminum oxide film by ALD technology, and the precursor is also aluminum alkyl (trimethyl aluminum). The above-mentioned aluminum precursors have good volatility and are widely used in existing CVD/ALD technologies, but all have the following problems:

(1) It is easy to decompose at room temperature, and its properties are extremely unstable. It has high requirements for storage equipment, and can be decomposed to generate hydrogen and metal aluminum during storage. Shipping and subsequent use.

(2) During the deposition of thin films by ALD, thermal decomposition reaction occurs due to the poor thermal stability of the precursor, accompanied by CVD, which severely limits the advantages of ALD.

SUMMARY OF THE INVENTION

The present invention is proposed to overcome the shortcomings of the above-mentioned prior art, and the technical problem it solves is to provide a series of stable properties at room temperature, not easy to decompose, convenient for storage and transportation, and excellent in volatility during practical application. Thermal decomposition, aluminum precursors suitable for ALD technology, and preparation methods and uses of such precursors.

The invention provides a novel thin film deposition aluminum precursor, which is characterized in that it has the molecular structure of structural formula (I):

wherein, R ₁ , R ₂ , R ₃ , R ₄ , and R ₅ represent a hydrogen atom, a C ₁ -C ₆ alkyl group, a C ₂ -C ₅ alkenyl group, a C ₃ -C ₁₀ cycloalkyl group, and a C ₆ -C ₁₀ Aryl or —Si(R ₀ ) ₃ , and halogen-substituted groups of the above-mentioned groups, wherein R ₀ is a C ₁ -C ₆ alkyl group or a halogen-substituted group thereof, R ₁ , R ₂ , R ₃ , R _4. R ₅ is the same or different.

The present invention also provides a method for preparing the above-mentioned novel thin-film deposition aluminum precursor, which is characterized by reacting according to the following chemical formula:

wherein R ₁ , R ₂ , R ₃ , R ₄ , R ₅ , R ₆ , R ₇ , R ₈ , R ₉ , R ₁₀ , and R ₁₁ represent a hydrogen atom, a C ₁ -C ₆ alkyl group, a C ₂ -C ₅ alkenyl, C ₃ -C ₁₀ cycloalkyl, C ₆ -C ₁₀ aryl or -Si(R ₀ ) ₃ , and halogen-substituted groups of the above groups, wherein R ₀ is C ₁ -C ₆ alkane R ₁ , R ₂ , R ₃ , R ₄ , R ₅ , R ₆ , R ₇ , R ₈ , R ₉ , R ₁₀ , and R ₁₁ are the same or different.

Wherein, the following steps are included: (1) placing the second reactant comprising alane in a reaction vessel, adding the solvent and stirring evenly, and adding the first reactant comprising aminopyridine or its derivative into the reaction vessel under low temperature conditions , stirring at room temperature or heating and stirring overnight; (2) filtering the mixture in step (1), concentrating at low pressure to obtain a small amount of solid-liquid mixture, adding a solvent, and leaving it to stand overnight to obtain colorless block crystals, that is, Precursor (I).

Wherein, the low temperature condition and/or the low temperature storage temperature is -78°C to 0°C, and any cooling means selected from the group consisting of liquid nitrogen, dry ice, liquid ammonia, low temperature circulating pump and combinations thereof are used.

Wherein, the time for stirring at room temperature or heating and stirring is 1 to 10 hours.

Wherein, the temperature of room temperature stirring or heating stirring is 25°C to 150°C.

Wherein, the molar ratio of the first reactant to the second reactant is 1.0:1.0 to 1.0:3.0.

Wherein, the solvent is selected from any one of the following organic solvents and combinations thereof: alkanes selected from C ₅ H ₁₂ -C ₈ H ₁₈ linear or branched alkanes, C ₅ H ₁₀ -C ₈ H ₁₆ cyclic alkanes; Aromatic hydrocarbons from benzene and toluene; ethers from diethyl ether and tetrahydrofuran.

The conditions for filtration and concentration of the reaction mixture are: pressure concentration at 25 to 80° C., and the pressure is 0.05 to 0.20 MPa.

The present invention further provides a method for manufacturing a semiconductor device, comprising using a CVD or ALD process to prepare a thin film containing aluminum, wherein the thin film is manufactured using the above-mentioned aluminum precursor, wherein the thin film comprises an aluminum metal thin film, a thin film containing aluminum Any one of an aluminum oxide film, an aluminum-containing nitride film, an aluminum-containing alloy film, and a combination thereof.

The beneficial effects of the present invention include:

(1) The introduction of a pyridine ring as a ligand can effectively reduce the activity of the precursor, and can generate a precursor compound with a larger molecular weight through the Al-Al and Al-N bonds, with improved stability and reduced volatility, which is convenient for storage. and transportation.

(2) The synthesis process is simple and clean, the raw materials are low, and the energy consumption is low, which is an environment-friendly and economical preparation method.

(3) The film-forming performance is excellent. Taking the scanning electron microscope (SEM) of the aluminum-containing thin film obtained from the precursor prepared in Example 1 as an aluminum source as shown in Fig. 2 as an example, the film-forming is uniform and dense.

This thin film deposition aluminum precursor effectively overcomes the shortcomings of the prior art, improves the efficiency of depositing thin films, and is widely used in the fields of semiconductor and nanotechnology.

Description of drawings

The technical solutions of the present invention are described in detail below with reference to the accompanying drawings, wherein:

Fig. 1 shows the thermogravimetric analysis pattern of the compound [Al ₂ H ₂ {N(2-C ₅ H ₄ N)n-Bu} ₂ ] according to Preparation Example 1 of the present invention, wherein the pattern analysis: the starting point of weight loss The temperature is 183.4°C, the temperature corresponding to 50% weight loss is 284.6°C, the end point temperature of weight loss is 311.8°C, and the residual mass is 1.76%.

FIG. 2 shows the scanning electron microscope (SEM) image of the aluminum-containing thin film obtained by using the precursor prepared in Example 1 as the aluminum source.

Figure 3 shows the thermogravimetric analysis spectrum of trimethylamine alane (TMAA), wherein, the spectrum analysis: at room temperature, the volatilization weight loss begins, the temperature corresponding to 50% weight loss is 86.3 °C, the weight loss termination point temperature is 111.5 °C, and the residual mass is 6.2%.

Fig. 4 shows the thermogravimetric analysis spectrum of dimethylethylamine alane (DMEAA), wherein, the spectrum analysis: start to lose weight by volatilization at room temperature, the temperature corresponding to 50% weight loss is 115.1°C, and the temperature at the end point of weight loss is 134.4°C, Residual mass was 7.1%.

Fig. 5 shows the thermogravimetric analysis pattern of dimethyl alanine hydride (DMAH), wherein, the pattern analysis: start to lose weight by volatilization at room temperature, the temperature corresponding to 50% weight loss is 124.9°C, the temperature at the end point of weight loss is greater than 200°C, and the residual The mass is 26.6%.

Detailed ways

The present invention will be further described below with reference to specific embodiments and accompanying drawings.

The new thin film deposition precursors described above are commonly used in various deposition films in the field of semiconductors and nanotechnology, such as aluminum films, aluminum oxide films, composite metal films and nano-thin films. The precursor provided by the invention has stable properties, is not easy to decompose, is convenient for storage and transportation, has good high-temperature volatility and excellent film-forming performance, and promotes the development of semiconductor and nanotechnology.

The present invention provides a series of aluminum precursors represented by structural formula (I):

wherein, R ₁ , R ₂ , R ₃ , R ₄ , and R ₅ represent a hydrogen atom, a C ₁ -C ₆ alkyl group, a C ₂ -C ₅ alkenyl group, a C ₃ -C ₁₀ cycloalkyl group, and a C ₆ -C ₁₀ Aryl or —Si(R ₀ ) ₃ , and halogen-substituted groups of the above-mentioned groups, wherein R ₀ is a C ₁ -C ₆ alkyl group or a halogen-substituted group thereof, R ₁ , R ₂ , R ₃ , R _4. R ₅ is the same or different.

The precursor of structural formula (I) can be synthesized by easily obtained pyridine and its derivatives and alane according to the following chemical reaction formula (1):

wherein R ₁ , R ₂ , R ₃ , R ₄ , R ₅ , R ₆ , R ₇ , R ₈ , R ₉ , R ₁₀ , and R ₁₁ represent a hydrogen atom, a C ₁ -C ₆ alkyl group, a C ₂ -C ₅ alkenyl, C ₃ -C ₁₀ cycloalkyl, C ₆ -C ₁₀ aryl or -Si(R ₀ ) ₃ , and halogen-substituted groups of the above groups, wherein R ₀ is C ₁ -C ₆ alkane R ₁ , R ₂ , R ₃ , R ₄ , R ₅ , R ₆ , R ₇ , R ₈ , R ₉ , R ₁₀ , and R ₁₁ are the same or different.

The preparation of the precursor compound of structural formula (I) includes the following steps: (1) placing the second reactant including alane in a reaction vessel, stirring the solubilizer evenly, and placing the first reactant including aminopyridine or its derivative in a reaction vessel; Add to the reaction vessel under low temperature conditions, stir at room temperature or heat and stir to react overnight; (2) filter the mixture in step (1), concentrate under low pressure to obtain a small amount of solid-liquid mixture, add a solvent, and let stand overnight to obtain no mixture. The color block crystal is the precursor (I).

Wherein, the low temperature condition and/or the temperature of low temperature preservation is -78°C to 0°C, and any cooling means and combination thereof selected from liquid nitrogen, dry ice, liquid ammonia, and low temperature circulating pump are used; the room temperature stirring or The time for heating and stirring is 1 to 10 hours; the temperature for stirring at room temperature or heating and stirring is 25°C to 150°C; the molar ratio of the first reactant to the second reactant is 1.0:1.0 to 1.0:3.0; The solvent is selected from any one of the following organic solvents and combinations thereof: alkanes selected from C ₅ H ₁₂ -C ₈ H ₁₈ linear or branched alkanes, C ₅ H ₁₀ -C ₈ H ₁₆ cyclic alkanes; Aromatic hydrocarbons from benzene and toluene; ethers selected from diethyl ether and tetrahydrofuran; the conditions for filtration and concentration of the reaction mixture are: pressure-concentrated at 25-80° C., and the pressure is 0.05-0.20 MPa.

The thin film obtained from the above-mentioned aluminum precursor (I) by the CVD/ALD process may include aluminum-containing thin films such as aluminum films, aluminum oxide films, and aluminum alloy films. In addition, the applications of the obtained thin films include, inter-metal interconnects, contact plugs, device terminals (source, drain, gate), device high-K insulating layers (eg, gate insulating layers of MOSFETs).

In the following, the applicant has made some specific experiments on the present invention, taking the preparation of the compound [Al ₂ H ₂ {N(2-C ₅ H ₄ N)n-Bu} ₂ ] as an example, and combining it with trimethylamine alane (TMAA ), dimethylethylamine alane (DMEAA) and dimethylaluminum hydride (DMAH) are used to compare properties, which are only used to describe the present invention in detail, and do not limit the scope of the invention in any way.

(1) embodiment one:

Place 10.0 mmol of trimethylamine alane in the reaction vessel, add n-hexane and stir evenly, then slowly add 10.0 mmol of 2-n-butylaminopyridine dissolved in toluene into the system at a low temperature of -78°C, and in the process of dropwise addition The system became turquoise translucent with bubbles emerging. After stirring at room temperature for 1 h, it was heated to 25 °C and refluxed overnight; the obtained mixture was filtered, concentrated at a low pressure of 0.05 MPa and a temperature of 25 °C to obtain a small amount of solid-liquid mixture. After standing overnight, colorless bulk crystals were obtained, namely compound [Al ₂ H ₂ {N(2-C ₅ H ₄ N)n-Bu} ₂ ], with a yield of 87%, and the serial number was denoted as 1#.

(2) embodiment two:

Place 15.0 mmol of trimethylamine alane in the reaction vessel, add n-hexane and stir evenly, then slowly add 10.0 mmol of 2-n-butylaminopyridine dissolved in toluene into the system at a low temperature of -56 °C, and in the process of dropwise addition The system became turquoise translucent with bubbles emerging. After stirring at room temperature for 3 hours, it was heated to 75 °C and refluxed overnight; the obtained mixture was filtered, concentrated at a low pressure of 0.1 MPa and a temperature of 45 °C to obtain a small amount of solid-liquid mixture. After standing overnight, colorless bulk crystals were obtained, namely compound [Al ₂ H ₂ {N(2-C ₅ H ₄ N)n-Bu} ₂ ], with a yield of 88%, and the serial number was denoted as 2#.

(3) embodiment three:

Place 20.0 mmol of trimethylamine alane in the reaction vessel, add n-hexane and stir evenly, then slowly add 10.0 mmol of 2-n-butylaminopyridine dissolved in toluene into the system at a low temperature of -39 °C, and in the process of dropwise addition The system became turquoise translucent with bubbles emerging. After stirring at room temperature for 5 h, it was heated to 105 °C and refluxed overnight; the obtained mixture was filtered, concentrated at a low pressure of 0.1 MPa and a temperature of 60 °C to obtain a small amount of solid-liquid mixture. After standing overnight, colorless bulk crystals were obtained, which was compound [Al ₂ H ₂ {N(2-C ₅ H ₄ N)n-Bu} ₂ ], with a yield of 86%, and the serial number was denoted as 3#.

(4) embodiment four:

Place 25.0 mmol of trimethylamine alane in the reaction vessel, add n-hexane and stir evenly, then slowly add 10.0 mmol of 2-n-butylaminopyridine dissolved in toluene into the system at a low temperature of -25 °C, and in the process of dropwise addition The system became turquoise translucent with bubbles emerging. After stirring at room temperature for 8 hours, it was heated to 150 °C and refluxed overnight; the obtained mixture was filtered, concentrated at a low pressure of 0.15 MPa and a temperature of 75 °C to obtain a small amount of solid-liquid mixture. After standing overnight, colorless bulk crystals were obtained, which was compound [Al ₂ H ₂ {N(2-C ₅ H ₄ N)n-Bu} ₂ ], the yield was 88%, and the number was denoted as 4#.

(5) embodiment five:

Place 30.0 mmol of trimethylamine alane in the reaction vessel, add n-hexane and stir evenly, then slowly add 10.0 mmol of 2-n-butylaminopyridine dissolved in toluene into the system at a low temperature of 0 °C. The system became turquoise translucent with bubbles emerging. After stirring at room temperature for 10 h, it was heated to 150 °C and refluxed overnight; the obtained mixture was filtered, concentrated at a low pressure of 0.2 MPa and a temperature of 80 °C to obtain a small amount of solid-liquid mixture. After standing overnight, colorless bulk crystals were obtained, which was compound [Al ₂ H ₂ {N(2-C ₅ H ₄ N)n-Bu} ₂ ], with a yield of 87%, and the serial number was 5#.

Table 1

As shown in Table 1 above, the prepared thin film precursor compound [Al ₂ H ₂ {N(2-C ₅ H ₄ N)n-Bu} ₂ ] (1#, 2#, 3#, 4#, 5# ) Compared with the aluminum precursors in the prior art, TMAA, DMEAA and DMAH all begin to lose weight by volatilization at room temperature, and the final residual amounts are all higher than 6.0%, even reaching 26.6%, indicating that these three aluminum precursors are extremely high temperature Easily decomposed, unstable in nature and high in danger. The temperature of the starting point of weight loss of the new aluminum precursor provided by the present invention is about 183° C., the temperature of 50% weight loss is about 284° C., and the final residual amount is reduced to 1.7%, showing high thermal stability, especially at room temperature. For stability, easy storage and transportation.

Although the invention has been described with reference to one or more exemplary embodiments, those skilled in the art will recognize that various suitable changes and equivalents may be made in process flow or material structure without departing from the scope of the invention. In addition, many modifications, as may be adapted to a particular situation or material, may be made from the disclosed teachings without departing from the scope of the invention. Therefore, the present invention is not intended to be limited to the specific examples disclosed as the best mode for carrying out the present invention, and the disclosed chemical formula structures of materials and methods of making the same are intended to include all implementations that fall within the scope of the present invention. example.

Claims (8)

1. a kind of film deposition of aluminum presoma, which is characterized in that the molecular structure with structure formula (I):

Wherein, R₁、R₂、R₃、R₄、R₅Indicate hydrogen atom.

2. a method of prepare a kind of film deposition of aluminum presoma as described in claim 1, it is characterised in that according to following Chemical formula reaction:

Wherein, R₁、R₂、R₃、R₄、R₅、R₆、R₇、R₈、R₉、R₁₀、R₁₁Indicate hydrogen atom.

3. method as claimed in claim 2, wherein the following steps are included:

It (1) will include that the second reactant of aluminium alkane is placed in reaction vessel, solubilizer stirs evenly, and will include the of amido pyridine One reactant is added in reaction vessel under cryogenic, is stirred at room temperature or heating stirring reaction is stayed overnight；The cryogenic conditions It is -78 DEG C to 0 DEG C, using selected from liquid nitrogen, dry ice, liquefied ammonia, any one cooling way of low-temperature circulating pump and combinations thereof；

(2) mixture in step (1) is filtered, low pressure concentration obtains minimal amount of solidliquid mixture, solvent is added, stands Overnight, colourless bulk crystals, as presoma (I) are obtained.

4. method as claimed in claim 3, wherein be stirred at room temperature or the time of heating stirring is 1 to 10 hour.

5. method as claimed in claim 3, wherein be stirred at room temperature or the temperature of heating stirring is 25 DEG C to 150 DEG C.

6. method as claimed in claim 3, wherein the molar ratio of the first reactant and the second reactant be 1.0:1.0 extremely 1.0:3.0。

7. method as claimed in claim 3, wherein solvent is selected from any one of following organic solvent and combinations thereof: being selected from C₅H₁₂ ~C₈H₁₈Linear chain or branched chain alkane, C₅H₁₀~C₈H₁₆The alkane of cyclic alkane；Aromatic hydrocarbon selected from benzene, toluene；Selected from ether, four The ethers of hydrogen furans.

8. a kind of method, semi-conductor device manufacturing method, described thin including preparing the film containing aluminium element using CVD or ALD technique Film is manufactured using aluminium presoma as described in claim 1, wherein the film includes aluminum metal film, the oxide containing aluminium Any one of film, the nitride film containing aluminium, the alloy firm containing aluminium and combinations thereof.